FR2508882A1 - SYSTEM FOR DETECTING THE PRESENCE OF THREADS ON A SPINNING CONTINUOUS - Google Patents

Abstract

THIS SYSTEM INCLUDES A SENSOR INCLUDING A MOBILE EQUIPMENT IN THE FORM OF AN ELECTRIC CIRCUIT 18 IN WHICH ARE PLACED TWO SOFT-BLADE SWITCHES 17 CLOSED BY A BALANCER 9 IN RESPONSE TO THE ENCOUNTER OF A WIRE. THE CIRCUIT 18 INCLUDES A CONDUCTOR 19 WIND UP ON A MAGNETIC CORE 20. THE INFORMATION TRANSPORT DEVICE INCLUDES A FIXED LOOP CONDUCTOR 23, PART 24 OF WHICH IS PARALLEL TO THE SENSOR'S PATH AND CROSSES CORE 20. MEANS ARE PROVIDED FOR. OSCILLATIONS IN THE LOOP CONDUCTOR 23, AS WELL AS MEANS DETECTING A VARIATION OF THE OSCILLATION CONDITIONS INDUCED BY A CHANGE OF STATE OF THE ELECTRIC CIRCUIT 18 DUE TO THE CLOSING OF A SWITCH 17 AND TRANSLATION OF THE ENCOUNTER OF A WIRE BY THE SENSOR. THE DETECTION OF VARIATIONS IN OSCILLATION CONDITIONS ALLOWS THE NUMBER OF BREAKS OF THE TEXTILE MACHINE TO BE DEDUCTED.

Description

CONTINUOUS WIRE PRESENCE DETECTION SYSTEM

TO SPIN

  The invention relates to a system for detecting the presence of threads on a textile machine of the type comprising a traveling sensor detecting the presence of a thread and translating this presence by electrical information, a motor device of the sensor, and a device for transporting information to a stationary information processing unit We know for example from the patent

  French No 2 002 208 of such detection systems.

  In general, these systems are more specifically designed to detect the presence (or absence) of a thread on a textile machine such as a continuous spinning by remote detection means, and in particular by

  photoelectric and electroacoustic devices.

  These means are delicate to implement and to regulate

  properly; moreover they often require an ali-

  mobile electrical mentation with the sensor, which poses

Connection problems.

  The object of the invention is in particular to propose a detection system in which one can dispense with any electrical supply to the sensor, while naturally allowing the transmission and detection of the electrical information corresponding to the

meeting a thread.

  This object is achieved by the fact that the sensor comprises a mobile assembly formed by an electrical circuit in which is placed at least one switch whose change of state translates the encounter of a wire by the sensor during its movement, said circuit

  electric being constituted by the winding of a con-

  conductor around a solid cylindrical magnetic core

  due to the sensor and the fact that the transfer device

  information port includes a fixed looped conductor, part of which is parallel to the sensor path and crosses the magnetic core, generating means

  of oscillation being provided to generate oscillations

  tions in the looped conductor as well as electronic means for detecting a variation in the conditions of oscillation induced by a change of state of the circuit

sensor.

  The change in state of the electrical circuit can be its closing or opening in response to the detection of a wire according to the arrangement of the sensor. This detection can be done by various means. It turns out that detecting the presence of a wire by contact is one of the most

  more reliable detection However, it is essential

  sand that this detection is carried out without influencing the formation of the wires, a condition which has not been satisfactorily satisfied until now by known contact detection devices, such as that shown

  in the aforementioned French patent No. 2,002,208.

  Another object of the invention is to propose a new detection system of the type mentioned, in which the contact detection means act with very great softness and

  very great flexibility, so as to remain without influence

son formation.

  For this purpose, the sensor is composed of a pendulum pivoting about a vertical axis, this pendulum comprising a groping horizontal rod urged by magnetic return means towards an equilibrium position from which it is likely to deviate when it encounters a wire during the displacement of the sensor, the balance also comprising at least one magnet cooperating with the flexible blade switch or switches placed in the electrical circuit of the sensor whereby a deviation of the feeler rod around its equilibrium position causes a change of state of the flexible reed switch and of the electrical circuit, thus reflecting the presence

of a wire.

  The change of state of the switch (and therefore of the circuit) can be its closing or its opening depending on whether the sensor is arranged so that a deviation of the balance around its equilibrium position

  approach or move the magnet away from the switch.

  In the event that a deviation from the balance causes the circuit to close, it is advantageous for the balance to comprise two magnets each associated with a flexible reed switch placed on a common electrical circuit, the switches being arranged in a position corresponding to the position d balance of their respective magnet angles of the same magnitude but opposite directions In this way, this device works both in a direction of movement of the sensor that

in the other.

  The number of wires encountered is counted by means which count the variations in the oscillation conditions of the looped conductor. By difference with the number of machine spindles (difference calculated automatically) we can know

  the number of wire breaks for the machine in question.

Although the sensor can be

  attached to a traveling organ normally fitted to the ma-

  textile china (pneumatic cleaner for example), we

  may also provide a support and driving device

specifically.

  Advantageously, the sensor is fixed on an endless belt passing around two pulleys

  at least one of which is connected to a motor.

  Advantageously, the motor is reversible.

  switch and limit switches are fitted at each end of the sensor path to reverse

engine rotation.

  The invention will be better understood on

  reading of the description which will follow in a mode of -

  preferred realization, description made in connection with

  the accompanying drawings in which: Figure 1 shows, in plan, the detection system of the invention; FIG. 2 represents, in schematic front view, the motor device of the detection system;

  FIG. 3 represents a view from

  tielle of the sensor of Figure 1, when the balance is deflected by the meeting of a wire; Figure 4 shows the diagram

  corresponding to the detection device.

  The device of the invention comprises a traveling sensor 1 capable of passing along a

keep spinning.

  The sensor 1 is fixed on an endless belt 2 At one end of the loom, the belt 2 wraps a pulley 3 driven directly or indirectly by a reversible motor 4 At the other end of the loom, the belt passes over a pulley

crazy with dismissal 5.

  Two guide pulleys 6 can

reduce congestion.

  The belt 2 and / or the sensor 1 are guided, over the entire length of the machine, by a double

rail 7 fixed to the frame.

  At each end of the rail 7, limit switches 8 reverse the rotation of the motor 4, by means of electrical connections

not shown.

  Instead of a reversible motor 4 driving the pulley 3, it is possible to provide two motors capable of driving the pulleys 3 and 5 respectively.

  in different directions, alternately.

  The sensor 1 includes a pendulum 9 -

  formed of three horizontal rods 10, 11, 12 balanced,

  and capable of pivoting about a vertical axis 13.

  The balance 9 has an equilibrium position in which it is returned by at least one fixed magnet 14 of the sensor cooperating with one of the magnets 15 located at the end of the rods 11 and 12 of the balance. The third rod, the feeler rod 10, extends substantially perpendicular to the path of the sensor, when the balance is in its equilibrium position. The assembly is placed so that, when the sensor 1 moves along the continuous spinning, the feeler rod 10 is capable of intercepting the wires 16 normally present on the

keep spinning.

  The sensor 1 also comprises two ILS bulbs (flexible blade switches) 17 capable of closing the same electrical circuit 18 composed of a conductor 19 wound around a cylindrical magnetic core 20, and possibly of a

  @ tuning capacity 21 The core 20 can be made of ferrite.

  in imphy steel, or in t 6 le of silicon for example.

The transport system for information

  training to the stationary processing unit 22 includes one or more looped conductive cables 23

  of which a part 24 is maintained substantially pa-

  parallel to the path of the sensor 1 (that is to say to the transport rail 7) and extends over at least the length of said path The magnetic cylinder 20 envelops the conductor of the part 24 and is capable of sliding

  along the length corresponding to the path of sensor 1.

  The processing unit 22 includes electronic means for generating oscillations

  in the looped conductor 23, and means for

  detect variations in oscillation conditions

in said conductor.

  These variations are induced by a change in state of the electrical circuit 18 of the sensor 1, corresponding to the closing of said circuit in response to a deviation of the balance caused by the encounter.

  a wire 16 on the path of sensor 1 (or more specified-

  ment on the path of the feeler rod 10), as well as

will explain it now.

  The sensor 1 driven by the belt 2 moves along the face of the continuous spinning at a speed of 15 to 20 m / lein, the movement being reversed at

each end of the machine.

  When the feeler rod 10 encounters a wire 16, the pendulum 9 swings clockwise (FIG. 3) or in the other direction, depending on the direction of travel of the sensor. One of the magnets 15 approaches a bulb ILS 17 which closes well

the electrical circuit 18.

  The balance is returned by the return magnet 14, the force or, preferably, the position is adjustable (arrow 25) The force required for tilting is minimal and has no influence on the

wire formation 16.

  The assembly integral with the sensor composed of the magnetic circuit 20 and the coil 19 constitutes

  part of a transformer whose winding 19 re-

presents the secondary.

  The primary of this transformer is

  constituted by the conductor (s) 24 stretched parallel-

  ment to rail 7 and passing inside the magnetic circuit: this primary winding is coupled to a

oscillating circuit 26.

  The short-circuit of the tuning capacity 21 or simply of the secondary winding 19 (short-circuit corresponding to the closing of one of the switches 17) causes a variation in the conditions

  oscillations and possibly stopping them.

  More precisely, if Lf designates the inductance of the choke formed by the cable 24 stretched along the loom and R its resistance, if Le designates the inductance of the coupling choke of the toroid 19-20 and C the value of the tuning capacity 21, the impedance Rp brought in parallel on the oscillating circuit 26 is written:

1 X 2

  Rp = (R + o N denotes the transformation ratio and X the reactance of the loop, with: when switch 17 is open, X * Lf W So if R is very small

before Lf W, Rp is important.

  when switch 17 is closed, X tends to zero, so Rpz L 2

  R being weak, Rp decreases strongly.

  To fix the ideas, the order of magnitude of Lf is a few Ju IH / m, R is a few 2 V) m and - * 50 k Hz The tuning capacity C is

  of the order of a few n F The coupling between self pri-

  mayor and loop 18 must be chosen so as not to load the oscillating circuit when switch 17 is open (Rp> 1 kfÈ) and to obtain Rp small (41 OQJL) when switch 17 is closed without using a sharp agreement It is this variation in impedance which

  causes the oscillation conditions to vary.

  The torus 20 is made from 2 ferrite cups usually used as magnetic shielding

  chokes for TV correction circuits.

  The coupling at the oscillating circuit 26 is also carried out from a cup

of the same type.

  It should be noted that this solution allows the use of several sensors on the same line and in particular allows the processing by the same assembly of

2 continuous faces.

  The role of the processing unit 22 is to count the number of closings of the switch 7, corresponding to the number of wires encountered on this path.

of the sensor.

  The detection principle can be

  based on an assembly comprising two monostable redeclen-

  chables which provide, at each oscillation stop (therefore each time switch 17 or more is closed

  exactly one of the two switches 17) of the front $ des-

  cendants that it suffices to count down conventionally-

  nelle. The initialization dal d 6 counter used takes place at each start of the sweep, the initialized value corresponding to the number of threads normally present on the continuous spinning At the end of sweeping, the content of the down counter therefore indicates the number of broken threads, which can be memorized, displayed and compared to a pre-established critical threshold according to which any excess triggers an alarm

visual or audible for example.

  Naturally, the processing unit 22 includes dials and controls making it possible to select the number of spindles of the loom to be checked, to display the number of broken wires, to select the threshold of broken wires beyond which an alarm is triggered, and control the drive motor

of the sensor.

Claims (1)

CLAIMS 1 System for detecting the presence of threads on a textile machine of the type comprising a traveling sensor detecting the presence of a thread and translating this presence by electrical information, a motor device of the sensor, and a device for transport of information to a stationary information processing unit, characterized in that the sensor comprises a moving element formed by an electrical circuit (18) in which is placed at least one switch (17), the change of state reflects the encounter of a wire (16) by the sensor during its movement, said electrical circuit (18) being constituted by the winding of a conductor (19) around a magnetic core (20) cylindrical integral with the sensor (1) and in that the information transport device comprises a fixed looped conductor (23), a part (24) of which is parallel to the path of the sensor (1) and passes through the core magnetic (20), means (26 i oscillation generators being provided for generating oscillations in the looped conductor (23) as well as electronic means for detecting a variation in the conditions of oscillation induced by a change of state of the electrical circuit (18) of the sensor (1) - 2 System according to claim 1, characterized in that the electrical circuit (18) of the sensor (1) also comprises a capacity (21). 3 System according to any one of claims 2 or 3, characterized in that the information processing unit (22) comprises means for counting variations in the oscillation conditions. 4 System according to any one of claims 1 to 3, characterized in that the sensor (1) consists of a balance (9) pivoting about a vertical axis, this balance comprising a horizontal feeler rod (10) biased by magnetic return means (14, 5) towards an equilibrium position from which it is liable to deviate when it encounters a wire (16) during the movement of the sensor (1), the balance (9) comprises as long as at least one magnet (15) cooperating with a switch (17) with flexible blades placed in the electrical circuit (18) whereby a deviation of the feeler rod (10) around its equilibrium position causes a change of state of the switch (17) with flexible blades and of the electrical circuit (18), thus reflecting the presence of a wire (16). System according to claim 4, characterized in that a deviation of the feeler rod (10) around its equilibrium position causes the closing of the electrical circuit (18). 6 System according to any one of claims 4 or 5, characterized in that the balance (9) comprises two magnets (15) each associated with a switch (17) with flexible blades placed on a common electrical circuit (18), the switches (17) being arranged in a position making with the equilibrium position of their respective magnet (15) angles of the same magnitude but in opposite directions. 7) System according to any one of claims 1 to 6, characterized in that the sensor (1) is fixed on an endless belt (2) passing around two pulleys (3,5), one of which (3) at least is connected to a motor (4). 8) System according to claim 7, characterized in that the motor (4) is reversible and in that limit switches (8) are mounted at each end of the sensor path (1) to reverse the rotation of the motor . 9) System according to any one of claims   1 to 6, characterized in that the sensor (1) is fixed to an itinerant member of normal equipment of the textile machine.